Gravity feed wickless fuel oil fired heater



Patented July 11, 1950 1 UNITED STATES PATENT OFFICE GiiAvI'rii wioxLEss FTJEL oIL FIRED HEATER Charles J. '1. McPherson; Gleveland, Ohio Application May '9, 1946; serial Ne. 668,584

. g 1 invention reiates to heaters and pantie-=- t ey to a heater in which mere efficient appli (iatioh of the heat to a heat exchanger is obta tied, and more efficieht transfer or heat from heat exchanger to the air to be heated results, ahg'is an improvement en the invention disclosed i Patent No. 2,128,155 issued to 'me on August 23, 1938. I I V For the purposes of illustration the invention is embodied in an on fired heater or the cabinet or space heater type, its application to "central furnaces, stoves, and other types of heaters using oil or other types of fuel being readmy; apparent from the following description.

In my above identified patent there is disclosed a heater having a cylindrical outer casing and a central hollow flame deflector therein for deflect= ing the flames or combustible media outwardly toward the outer wall of the casing. Thus the deflector and casing form an annular passage or combustion chamber for the combustible media supplied by the burner. Such a structure, while bein eiiectivel for its intendedpurposes is open tothe' objection that the combustible mediatend towhirl in the annular passage about the upright axis thereof, and thus reach the exhaust stack too rapidly and without contacting the insurfaee or the outer jw'au er the casing eme fitly. 7 Again in the patented structure, the seccheery air must be drawn downwardly through theheated deflector prior to its introductie'n into the combustion chamber and, since it is heated and hor hany tends to rise during such passage, the stack pan is not utilized to the best advantare.

Cine oi the principal objects of the present invention is to effect better application of the heat to the heat exchange Walls of a heater. i Another object is to increase the heat exchange surface of a heater without materially increasing its overall size. A further object is to provide for a better flow of air to be heated and an improved heat exchange relationshipbetween the air and the heat exchanger of a heater. Other objects and advantages will becomeapparent from the following description wherein reference is made to the drawings, in which:

-tigure i is'a perspective view of a heater emt sting the principles of the present invention. Figure is a vertical "sectional view of the heater illustrated in Figure l and is taken on line 2-4 thereof. Figure 3 is'a horizontal sectional view iiiust ating a modified form of the heater; and 4 is a-p'ers ectiveview illustrating a modi= t claims. (01; arr--93)v 2 iid form of a fire pot which may be used in com nect'ion with the heater.

The heater of the present invention, indicated generally at i, comprises an upright hollow metal casing of channel shaped horizontal section throughout its length, the casing preferabl being formed of an outer hemi-cylindrical outer wan '2 and a coaxial hemi-cylindrical deflector Wall 3 Which is spaced radially of the upright axis inwardly from the outer wall 2 and which has tangential sidewall portions l which extend to and join the outer wall 2 at one side of the easing";

The walls 2, 3 and t define an upright com-- 5 bustion' chamber of channel shaped horizontal section, indicated generally at '6, and an air pas sage 1 of channel shaped horizontal section which is coextensive ehdwise with the combustion chambe! and 'exteii'olsalong one side thereof. The walls 3 and 4 also provide a deflector within the chamher B to prevent swirling of the combustible media and products of combustion in a spiral path about the upright axis of the casing.

The passage 1 is open both at the top and bottom and for its full extent 'endwise of the casmg. The combustion chamber 6 is closed at the top by a top wall 8 whichhas an exhaust passage 9 therein for venting the exhaust products from the interior of the combustion chamber 6. If desired, the exhaust passage may be provided in the wall 2, near the top wall 8. A suitable exhaust stack it is connected to the top wall and is in communication with the passage 9 and extends in overhangingvertically spaced relationship to the upper end of the passage 1 so that heated air rising through the passage '1 strikes the stack I!) and is deflected laterally there-around and 'recuperates' heat therefrom.

The bottom of the casinghas marginal flanges on which rests a removable horizontal bottom wall or fire ring II which closes the bottomof the combustion chamber. The ring H has a slot [2 therein which is preferably parallel to and spaced radially from the outer wall 2 of the casing and from the hemi cylihdrical portion of the wal1 3. The slot I2 is operative to admit conibustible media into the bottom of chamber 6 upwardlyand in spaced relation to the upright walls thereof.

In order to admit secondary air into the combustion chamber, a suitable header I4 is provided and is preferably arranged above the level of, but close to, the ring ll. The header I4 is located within the passage 1, A plurality of radial tubes or ducts l5 connect the header l4 and casing "'l and are in communication with the interior of the hollow header I4 and with the combustion chamber 6. A suitable conduit I6 is connected to the header I4 and extends outwardly beyond the outer limits of the casing I and is open at its outer end, as indicated at IT, to admit secondary air which is drawn through the header due to the stack draft. The secondary air is directed by the tubes I5 radially into the combustible media issuing from the slot l2.

The combustible media may be supplied through the slot I2 in the chamber 6 from any suitable source, but for the purposes of illustration it is supplied, in the same manner as'described in my above identified Letters Patent, from an oil burning fire pot. The fire pot comprises a container which, in horizontal section, is of substantially the same shape as the casing. The fire pot has an outer wall 2I and a coaxial inner wall 22 with tangential wall portions 23 joining the inner and outer walls so as to form a channel shaped air passage 24 which, when the fire pot and casing are assembled, forms a continuation of passage I. The passage 24 is opened at both the top and bottom. The fire pot 23 has outer and inner marginal portions 25 and 26, respectively, which engage the marginal flanges of the bottom of the casing for supporting the casing in coaxial alignment with the fire pot. If desired, the walls 25 and 26 may be secured permanently to the base marginal flanges of the casing or may be detachably connected thereto by suitable bolts.

Oil is admitted into the fire pot through a suitable branched feed line 27 which communicates with the fire pot near the bottom and which is connected to a suitable source of oil of substantially constant level so that the level of oil in the fire pot is maintained substantially constant. The walls 2i and 22 are provided with the plurality of ports 28 and admit primary air into the fire pot. Suitable legs 29 may be provided on the fire pot or, if desired, on a separate frame, for supporting the fire pot in spaced relation above the floor.

As more fully described in my above identified patent, the entire structure herein disclosed may be mounted in a suitable decorative casing having adequate openings at the top and bottom for permitting circulation of air into'intimate heat exchange relationship with walls 2, 3 and 4. In such a case, the legs 29 may be fastened to the decorative casing, but the heater may be used in the form illustrated without a decorative casing if desired.

Referring next to Figure 3, a heater such as illustrated in Figures 1 and 2 is disclosed, the heater comprising a casing having an outer wall 30 and an inner wall 3I' arranged so as to form a chamber and air passage of channel shaped horizontal section, as heretofore described. The casing is supported on a fire pot 32 having an annular slot 33 similar to slot I2 and communicating with the interior of the casing in the same manner. Instead of secondary air header I4 heretofore described, however, an annular header 34 is provided and is mounted in the same relationship as header I4. The annular header 34 of substantially the same height and capacity as the header I4 is provided and discharges into the combustion chamber through a plurality of radial ports 35. A conduit 36 extends radially from the header 34 for admitting secondary air. By the use of header 34, there is less obstruction to the air passage defined by the wall 3I so that a maximum flow of air through the exterior air passage defined by the wall 3| is permitted.

Referring next to Figure 4, there is illustrated a fire pot such as described in my above identified patent but modified so as to be cooperable with the casing herein described. The fire pot 31 is annular in horizontal section and to adapt it for cooperation with the channel type casing, a plate 38 is provided. The plate 38 has a central passage 39 corresponding in diameter to the diameter of the wall 3 of the casing illustrated in Figure 1. The plate 38 overlies and blocks out that portion of the top wall of the fire pot 31 which corresponds in horizontal section to the passage I. The plate also has a peripheral marginal flange 40 adapted to be received in snug face to face contact with the hemi-cylindrical wall 3 and tangential wall portions 4 of the eas- With the structure described, the upwardly directed combustible media in the fire pot are prevented from swirling about the upright axis of the casing 2 or combustion chamber 6 and thus remain for a longer period in the combustion chamber and in better heat exchange relationship to the walls 2, 3 and 4. At the same time a greater heat exchange surface is provided for a heater of given overall size, an eflicient and adequate fiow of air better proportioned to the amount of heat provided is obtained, and secondary air fOr sustaining combustion is introduced more effectively.

I-Iaving thus described my invention, I claim:

1. A heater comprising an upright hollow metal casing of channel shaped horizontal section throughout its length and having spaced inner and outer upright Walls of channel shaped horizontal section and a top wall closing the space between the upright walls, said walls providing a single channel shaped combustion chamber and an open top channel shaped air passage exteriorly thereof, means to introduce combustible gaseous media into the bottom of the chamber upwardly and in spaced relation to said upright walls, and an exhaust stack in communication with the chamber and extending in overhanging vertically spaced relation to the open top of the channel shaped air passage.

2. A heater comprising an upright hollow metal casing of channel shaped horizontal section having an outer upright wall of channel shaped horizontal section, an upright deflecting wall of channel shaped horizontal section extending from one side of the casing inwardly towards the opposite side thereof and being in spaced relation between its lateral edges, to the outer wall at said opposite side, and being coextensive with the outer wall endwise, and providing a single combustion chamber of relatively deep channel shaped horizontal section between the Walls and a single channel shaped air passage exteriorly of the chamber, a top wall connected to the top of the upright walls and closing the top of the chamber, a fire pot beneath the chamber and adapted to contain liquid fuel and supporting the casing and having a horizontal section of substantially the same shape as the casing, and wall means between the bottom of the chamber and top of the fire pot having a passage in spaced relation to the upright walls of the casing for admitting combustible media from the fire pot into the chamber, said casing having an exhaust passage at its upper end.

3. A heater comprising an upright hollow metal casing of channel shaped horizontal section for 16 its entire length and providing a single channel shaped combustion chamber and a substantially coaxial, channel shaped air passage along the exterior thereof, said passage being open at both ends, a top wall closing the upper end of they chamber, a fire pot closing the lower end of the chamber and in communication therewith, said fire pot being of substantially the same horizontal section as the casing, said casing having an exhaust passage spaced above the level of the fire-,-

pot. v

4. A heater comprising an upright metal casingof channel shaped horizontal section having at one side an outer upright wall of chan nel shaped horizontal section throughout its length and having at its opposite side an up-- right deflecting wall of smaller channel shaped horizontal section throughout its length, said defleeting wall, between its lateral edges, extend-5 ing, inwardly of the casing toward the upright wall and being in spaced relation thereto and coextensive therewith endwise of the casing, said walls providing a single upright combustion chamber of relatively deep channel shaped horizontal section and a single upright air passage of channel shaped horizontal section exteriorly of the chamber, a top wall connected to the top of the upright walls enclosing the top of the chamber, a fire pot, adapted. to contain liquid fuel, beneath the chamber and supporting the casing, a generally horizontal fire ring between the bottom of the chamber and the top of the fire pot and having an elongated slot therethrough in spaced relation from the upright walls for admitting combustible media from the fire pot into REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS- Number Name Date 42,893 Wilburn May 21, 1864 1,944,497 Crick Jan. 23, 1934 2,128,155 McPherson Aug. 23, 1938 2,250,146 Williams July 22, 1941 2,355,417 Breese Aug. 8, 1944 

